The present disclosure relates to a nonaqueous electrolyte solution that is used in a secondary battery, a secondary battery using the nonaqueous electrolyte solution, and a battery pack, an electrically driven vehicle, a power storage system, an electrically driven tool, and an electronic apparatus which use the secondary battery.
Recently, various electronic apparatuses such as a portable phone and a personal digital assistant (PDA) have been spreading widely, and a further reduction in size and weight, and a long operational lifespan of the electronic apparatuses are strongly demanded. Along with this, development of a battery as a power supply, particularly, a secondary battery which is small in size and is light in weight and which can obtain a high energy density has progressed.
Recently, application of the secondary battery to various uses has been examined without limitation to the above-described electronic apparatuses. Examples of the application includes a battery pack that is detachably mounted in an electronic apparatus, an electrically driven vehicle such as an electric vehicle, a power storage system such as a power server for home use, and an electrically driven tool such as an electrically driven drill.
To obtain a battery capacity, secondary batteries using various charging and discharging principles have been suggested, and among these, a secondary battery using intercalation and deintercalation of an electrode reaction material or precipitation and dissolution of the electrode reaction material has attracted attention. This is because the secondary battery can obtain an energy density higher than that of a lead battery, a nickel cadmium battery, and the like.
The secondary battery includes a nonaqueous electrolyte solution in combination with a positive electrode and a negative electrode. The positive electrode includes a positive electrode active material that participates in a charging and discharging reaction, and the negative electrode includes a negative electrode active material that participates in the charging and discharging reaction. The nonaqueous electrolyte solution includes a nonaqueous solvent and an electrolyte salt. A composition of the nonaqueous electrolyte solution has a great effect on battery characteristics, and thus various examinations have been made with respect to the composition of the nonaqueous electrolyte solution.
Specifically, to improve charging and discharging cycle lifespan characteristics and the like, a compound that contains boron (B) as a constituent element is contained in the nonaqueous electrolyte solution (for example, refer to Japanese Unexamined Patent Application Publication Nos. 2008-027782, 2009-245829, 2010-212153, and 2013-098057). Examples of the compound include boronic acid compound and the like.